The National Electrical Code (NEC) is used in all 50 states and governs electrical wiring and installations. The NEC applies to all types of buildings, including homes, schools, hospitals, offices, factories, warehouses, restaurants, bars, stores, shopping malls, etc. It also covers any type of facility that has electricity involved with its operation or use.
The NEC requires certain safety measures be taken to protect people from electrical hazards. It also requires certain procedures be followed to ensure the proper treatment of waste electrical materials (WEM).
Electrical wiring within a building or other structure is called "distribution wiring". This wiring provides power to different parts of the building, such as lighting, appliances, and equipment needed for heating and air-conditioning. Power goes into this distribution wiring at one end and comes out the other. Distribution wiring can be either internal or external. Internal distribution wiring carries power from a central point through walls and floors throughout the building. External distribution wiring brings power into the building via poles or conduits located on the property. This article focuses on internal wiring.
Internal wiring includes cable trays, risers, wireways, and raceways.
The NEC specifies the bare minimum for safe electrical systems. The NEC guidelines ensure that electrical systems are fundamentally free of dangers to persons and property. The NEC also establishes recommended practices to meet the needs of certain applications subject to specific requirements in other codes or regulations. For example, if you need your system to be accessible for maintenance work or have equipment that could get damaged by excessive voltage, then it is necessary to comply with those requirements of the NEC.
In addition to minimum safety standards, the NEC includes maximum current and voltage limits for all parts of the circuit. These limits may not be exceeded without causing harm to either people or property. For example, an electric heater that produces 8,000 watts requires a supply of 12 volts for its heating elements after taking into account any resistance from other factors such as wiring. If the heater is connected directly to a 110-volt power source, the current would be over 14 amps, which exceeds the limit for normal household wiring (12 amps). However, if the heater were part of a branch-circuit system with two 10-amp circuits, the current would be 2 amps per circuit, or 20 amps total, which is within acceptable limits.
Also under the NEC: safety clearance distances for electrical equipment, fire prevention measures, testing procedures for electrical systems, and more.
The National Electric Code (NEC), often known as NFPA 70, is a United States standard for the safe installation of electrical wiring. It was first published by the Northeast Electric Consortium in 1951 and has been revised several times since then. The current version is published by the NEC Foundation at www.nerc.org.
In general, the code requires that all non-metallic conductors inside buildings be enclosed in conduit or cable trays. The metal parts of power circuits must be protected from contact with water and exposed insulation should be removed from electricity-carrying parts of cables. Other than that, the code allows for other methods of enclosing cables so long as they meet certain requirements set out in the document.
The NEC contains detailed information on the type of construction and materials to use when installing wiring. In addition, it provides guidelines for the location and size of outlets, circuit breakers, and switches. Finally, it sets forth safety standards for electrical equipment used in residential settings.
The most important thing for any homeowner to know about the NEC is that it is always good practice to protect live wires from being touched by anyone who might be tempted to work on an electric system without proper protection.
9. The NEC excludes electrical installations in ships, boats, railway rolling stock, airplanes, and automobiles. The Code applies to underground mine installations as well as self-propelled mobile surface mining machines and the electrical trailing wires that go with them.
10. The NEC requires certain equipment used in electricity distribution or transmission to be listed as approved protective devices. For example, circuit breakers must be listed as approved protective devices. Not only does this ensure that the proper type of breaker is used to protect people from being shocked by broken cables but it also indicates to the installer how to use the breaker in a specific situation. Circuit breakers can be used to interrupt the power supply to a section of an electric system in order to prevent damage caused by overloading or shorting. Other types of protective devices include fuse panels, transformer enclosures, and voltage stabilizers. Equipment not listed as approved protective devices cannot be used instead; for example, if a ground rod is used as a protective device instead of a circuit breaker, then it cannot be labeled as such. Ground rods are designed to provide an electrical connection between buildings on a residential street and allow current to flow through them when metal objects are placed into service properly. But they are not intended to provide protection against lightning strikes or other external hazards since this function must be provided by other methods.
11. The NEC requires equipment used in electricity collection to be listed as approved receptacles.
Adopted in all 50 states, NFPA 70, the National Electrical Code (NEC), is the benchmark for safe electrical design, installation, and inspection to protect people and property from electrical hazards. The NEC requires specific conductors be used in residential wiring systems and specifies their placement and treatment. It also requires that all other conductors be protected by a continuous metal sheath - either aluminum or copper - except at terminal blocks, where they can be separated with only a thin bit of rubber insulation between them.
The NEC differentiates between two types of circuits: branch circuits and feeder circuits. Branch circuits are defined as "a number of outlets or lights controlled by one switch or circuit breaker." Feeders are defined as "the wires that carry current from a main panel to various parts of the house."
Branch circuits must be separated from ground by at least 1/0 AWG wire. This is for safety reasons: if there was no separation between these circuits they could short together, which would cause power to go to whatever outlet happens to be on the opposite side of the room from the ground wire.
The second type of circuit required by the NEC is called a "third-party" circuit. Third-party circuits provide power to devices that are not part of the original wiring system.
The National Electrical Code (NFPA 70 of the National Fire Protection Association) is a commonly used model code for the installation of electrical components and systems. Its objective is to protect persons and property from the dangers associated with the usage of electricity NEC 90.1 (A).
The code consists of rules on the location, construction materials, and maintenance practices for all types of electrical installations. It also includes performance standards for equipment such as circuit breakers, wiring devices, and appliances such as heaters, air conditioners, and dryers. The code is published by the NFPA and is updated annually. There are also local codes that vary from area to area. If you are working in an area that uses a different set of guidelines than what is shown in the NEC, then you should follow those procedures as well.
In addition to the NFPA 70 electrical code, there are other relevant codes that apply to specific industries. For example, the International Electrotechnical Commission's (IEC) 60603-1 standard is focused specifically on electrical installations in buildings involving one or more lift stations. This code was developed because elevators pose special risks to electrical systems. Elevator motors can draw a lot of current when they are first started or when they are taking someone up or down quickly. This can cause damage to other parts of the electric system if the proper precautions are not taken.